Discipline: Ecology Environmental and Earth Sciences
Subcategory: STEM Research
Maruthi Sridhar Balaji Bhaskar - Texas Southern University
Co-Author(s): Mark Bevelhimer and Mark Peterson
Monitoring of mercury (Hg) accumulation in fish has been conducted in East Fork Poplar Creek (EFPC) in Oak Ridge, Tennessee since 1985 under the Biological Monitoring and Abatement Program (BMAP). The bioaccumulation of Hg in EFPC fish has proven to be enigmatic over the past several years, with remedial actions at the industrial facility in the creek’s headwaters successfully decreasing total Hg concentrations in water, but not resulting in commensurate decrease in fish Hg concentrations. The primary goal of this project was to develop a model to understand the Hg loading and distribution in the EFPC watershed. Specific objectives of the project includes: 1) modeling the transport and fate of Hg through the 20 km stretch of EFPC; 2) to simulate and analyze the Hg loading from different sources; and 3) to evaluate the outcomes of different possible future scenarios in the region. A simulation model using STELLA™ was developed using an object-oriented modeling environment to simulate and analyze the Hg loading, distribution and bioaccumulation patterns in the EFPC. The model comprises of five interactive sectors namely: Water flow, Total Suspended Solids, Total Mercury, Methyl Mercury and Fish bioaccumulation. These sectors are interlinked and changes in one sector will impact other sectors through feedback loops between sectors. Key parameters in the model include erosion, mercury dissolution, methylation factor, and bioaccumulation factor. The STELLA model results showed that in general, the Hg bioaccumulation increased in downstream reaches of EFPC. The rate of Hg bioaccumulation depended not only on the erosion and water flow but also on the rate of Hg dissolution, methylation and bioaccumulation factors. The model was calibrated to match field results so that alternative situations could be simulated in future. This study suggests that the model, developed with STELLA, is a useful tool for estimating Hg dynamics in EFPC.
Funder Acknowledgement(s): This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Visiting Faculty Program (VFP) and by the National Science Foundation (NSF) under the award.
Faculty Advisor: None Listed,